class_docstr: A file-ish object that can have new data loaded into it.
  
  You can also push and pop line-matching predicates onto a stack.  When the
  current predicate matches the current line, a false EOF response
  (i.e. empty string) is returned instead.  This lets the parser adhere to a
  simple abstraction -- it parses until EOF closes the current message.
code: def pushlines(self, lines):
      self._lines.extend(lines)
  
imports: import re
  from email import errors
  from email._policybase import compat32
  from collections import deque
  from io import StringIO
label_desc: Use image node_id 8 for calling the BufferedSubFile obj's underlying member method code with example usage: obj.pushlines(lines) without return types